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प्रश्न
Identify the figure and give its use.
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उत्तर
Figure: Cartridge type fuse/Electric fuse
Uses:
- It is a safety device that protects the wiring from overheating caused by an excessive current supply.
- It melts when a high current travels through the circuit, causing the circuit to break and the current to stop flowing through it.
संबंधित प्रश्न
Why does the cord of an electric heater not glow while the heating element does?
An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
Derive the expression for the heat produced due to a current 'I' flowing for a time interval 't' through a resistor 'R' having a potential difference 'V' across its ends. With which name is this relation known?
The current passing through a room heater has been halved. What will happen to the heat produced by it?
The heat produced by passing an electric current through a fixed resistor is proportional to the square of:
(a) magnitude of resistance of the resistor
(b) temperature of the resistor
(c) magnitude of current
(d) time for which current is passed
Which of the following characteristic is not suitable for a fuse wire?
(a) thin and short
(b) thick and short
(c) low melting point
(d) higher resistance than rest of wiring
Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.
An electric iron is connected to the mains power supply of 220 V. When the electric iron is adjusted at 'minimum heating' it consumes a power of 360 W but at 'maximum heating' it takes a power of 840 W. Calculate the current and resistance in each case.
An electric iron of 1100 W is operated for 2 hrs daily. What will be the electrical consumption expenses for that in the month of April? (The electric company charges Rs 5 per unit of energy).
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Give scientific reason :
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster, etc., an alloy such as Nichrome is used, not pure metals.
Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.
Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
Answer the following question.
Write the mathematical expression for Joule's law of heating.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
What is the heating effect of electric current?
What is overloading?
Write two devices based on the heating effect of electric current.
What does overloading cause?
Define fuse.
Assertion: Bending of wire decreases the resistance of the electric wire.
Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.
What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.
An electric component used as a safety device is electric circuit is ______.
Name two electric devices for each where
- heating effect of current is used and
- magnetic effect of current is used.
Explain the working of an electric fuse.
It would cost a man Rs. 3.50 to buy 1.0 kW h of electrical energy from the Main Electricity Board. His generator has a maximum power of 2.0 kW. The generator produces energy at this maximum power for 3 hours. Calculate how much it would cost to buy the same amount of energy from the Main Electricity Board.
The following is not a safety device.
An electric fuse is a wire made up of a material having ______ melting point.
An electrochemical cell converts ______ energy into ______ energy.
Explain why fuse wire is always connected in a series arrangement.
Two students decided to investigate the effect of water and air on iron object under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object were removed, dried and their masses were measured. The table shows their results.
| Student | Object | Mass of Object before Rusting in g |
Mass of the coated object in g |
| A | Nail | 3.0 | 3.15 |
| B | Thin plate | 6.0 | 6.33 |
What might be the reason for the varied observations of the two students?
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
| A | B | C | D |
 |
 |
 |
 |
An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.
